Wood adhesive is a most commonly used adhesive, and has a total usage amount over a half of the total usage of adhesives. More than 80% of wood adhesives include at least one of a urea-formaldehyde resin and a phenolic-formaldehyde resin. However, the said resin will release a formaldehyde gas for even more than ten years due to their curing mechanism, not only seriously polluting the environment but also causing harm to human bodies. Therefore, it has become a prominent task for the technology field of wood adhesive to resolve the said problems of formaldehyde gas releasing and environmental pollution.